xsigo: hard LOCKUP in freeing paths

Orabug: 24669507

When path->users becomes zero uVNIC driver starts
cleaning up the Forwarding table entries.

In some corner cases the call is invoked from transmit
function which is in interrupt context and that results
in a hard LOCKUP.

With new changes path->users is decremented in transmit
function to allow cleanup to happen from other thread.
Proper care is taken to avoid race between these
two contexts.

Reported-by: chien yen <chien.yen@oracle.com>
Signed-off-by: Pradeep Gopanapalli <pradeep.gopanapalli@oracle.com>
Reviewed-by: Aravind Kini <aravind.kini@oracle.com>
Reviewed-by: viswa krishnamurthy <viswa.krishnamurthy@oracle.com>
Reviewed-by: Manish Kumar Singh <mk.singh@oracle.com>
Reviewed-by: UmaShankar Tumari Mahabalagiri <umashankar.mahabalagiri@oracle.com>

diff --git a/drivers/infiniband/ulp/xsigo/xscore/Makefile b/drivers/infiniband/ulp/xsigo/xscore/Makefile
index 06e05f91bd64855af643df2bdd74a0ce3ce2ecd2..4d6ee34ba069b46461e2ed4d6d4f2dc6a154786c 100644 (file)
--- a/drivers/infiniband/ulp/xsigo/xscore/Makefile
+++ b/drivers/infiniband/ulp/xsigo/xscore/Makefile
@@ -2,7 +2,7 @@ obj-$(CONFIG_INFINIBAND_XSCORE) := xscore.o
 xscore-y := xscore_impl.o xs_ud.o xscore_api.o xsmp.o \
            xscore_stats.o xscore_uadm.o
 
-ccflags-y += -DXSIGO_LOCAL_VERSION=\"6.0.r8031\"
+ccflags-y += -DXSIGO_LOCAL_VERSION=\"6.0.r8033\"
 ccflags-y += -DRDMA_PORT_LINK_LAYER_CHANGES -DHAS_SKB_ACCESS_FUNCTIONS
 ccflags-y += -DSCSI_STRUCT_CHANGES -DSCSI_TIMEOUT_CHANGES -DLLE
 ccflags-y += -DXG_FRAG_SIZE_PRESENT -DXG_FRAG_PAGE_PRESENT

diff --git a/drivers/infiniband/ulp/xsigo/xsvhba/Makefile b/drivers/infiniband/ulp/xsigo/xsvhba/Makefile
index 08e128851670173766296d90732ee5979c4b547f..5d562d1ac5ef5e95d36222b88e67563dab79bbc9 100644 (file)
--- a/drivers/infiniband/ulp/xsigo/xsvhba/Makefile
+++ b/drivers/infiniband/ulp/xsigo/xsvhba/Makefile
@@ -3,7 +3,7 @@ xsvhba-y := vhba_main.o vhba_xsmp.o vhba_create.o vhba_init.o vhba_delete.o \
            vhba_attr.o vhba_wq.o vhba_proc.o vhba_stats.o vhba_ib.o        \
            vhba_scsi_intf.o vhba_align.o
 
-ccflags-y += -DXSIGO_LOCAL_VERSION=\"6.0.r8031\"
+ccflags-y += -DXSIGO_LOCAL_VERSION=\"6.0.r8033\"
 ccflags-y += -DRDMA_PORT_LINK_LAYER_CHANGES -DHAS_SKB_ACCESS_FUNCTIONS
 ccflags-y += -DSCSI_STRUCT_CHANGES -DSCSI_TIMEOUT_CHANGES -DLLE
 ccflags-y += -DXG_FRAG_SIZE_PRESENT -DXG_FRAG_PAGE_PRESENT

diff --git a/drivers/infiniband/ulp/xsigo/xsvnic/Makefile b/drivers/infiniband/ulp/xsigo/xsvnic/Makefile
index 3f4edcdcc46cc78acb90c3a433f999c074f1c448..7d856ea2d029bd56f527815470bc7e14f7176052 100644 (file)
--- a/drivers/infiniband/ulp/xsigo/xsvnic/Makefile
+++ b/drivers/infiniband/ulp/xsigo/xsvnic/Makefile
@@ -1,7 +1,7 @@
 obj-$(CONFIG_INFINIBAND_XSVNIC) := xsvnic.o
 xsvnic-y := xsvnic_main.o xsvnic_stats.o
 
-ccflags-y += -DXSIGO_LOCAL_VERSION=\"6.0.r8031\"
+ccflags-y += -DXSIGO_LOCAL_VERSION=\"6.0.r8033\"
 ccflags-y += -DRDMA_PORT_LINK_LAYER_CHANGES -DHAS_SKB_ACCESS_FUNCTIONS
 ccflags-y += -DSCSI_STRUCT_CHANGES -DSCSI_TIMEOUT_CHANGES -DLLE
 ccflags-y += -DXG_FRAG_SIZE_PRESENT -DXG_FRAG_PAGE_PRESENT

diff --git a/drivers/infiniband/ulp/xsigo/xve/Makefile b/drivers/infiniband/ulp/xsigo/xve/Makefile
index 1f038eabdbc4f01f465316f8fb0efdd13dfd008b..cfcef1d93119830e0239fffb344827078bdda7e0 100644 (file)
--- a/drivers/infiniband/ulp/xsigo/xve/Makefile
+++ b/drivers/infiniband/ulp/xsigo/xve/Makefile
@@ -2,7 +2,7 @@ obj-$(CONFIG_INFINIBAND_XVE) := xve.o
 xve-y := xve_main.o xve_verbs.o xve_multicast.o xve_ib.o xve_tables.o \
         xve_ethtool.o xve_cm.o xve_stats.o
 
-ccflags-y += -DXSIGO_LOCAL_VERSION=\"6.0.r8031\"
+ccflags-y += -DXSIGO_LOCAL_VERSION=\"6.0.r8033\"
 ccflags-y += -DRDMA_PORT_LINK_LAYER_CHANGES -DHAS_SKB_ACCESS_FUNCTIONS
 ccflags-y += -DSCSI_STRUCT_CHANGES -DSCSI_TIMEOUT_CHANGES -DLLE
 ccflags-y += -DXG_FRAG_SIZE_PRESENT -DXG_FRAG_PAGE_PRESENT

diff --git a/drivers/infiniband/ulp/xsigo/xve/xve_cm.c b/drivers/infiniband/ulp/xsigo/xve/xve_cm.c
index d3853d039e006875f22f83c9e44817ca02e656d4..78c83ea9ef79ca4beb4f46a949ce34a66221b07f 100644 (file)
--- a/drivers/infiniband/ulp/xsigo/xve/xve_cm.c
+++ b/drivers/infiniband/ulp/xsigo/xve/xve_cm.c
@@ -1224,7 +1224,6 @@ void xve_cm_destroy_tx_deferred(struct xve_cm_ctx *tx)
        clear_bit(XVE_FLAG_OPER_UP, &tx->flags);
        if (test_and_clear_bit(XVE_FLAG_INITIALIZED, &tx->flags)) {
                list_move(&tx->list, &priv->cm.reap_list);
-               xve_cm_set(tx->path, NULL);
                xve_queue_work(priv, XVE_WQ_START_CMTXREAP);
        }
        spin_unlock_irqrestore(&priv->lock, flags);
@@ -1282,6 +1281,7 @@ static void __xve_cm_tx_reap(struct xve_dev_priv *priv)
                if (p->path)
                        xve_flush_single_path_by_gid(dev,
                                                     &p->path->pathrec.dgid);
+               xve_cm_set(p->path, NULL);
                xve_cm_tx_destroy(p);
                netif_tx_lock_bh(dev);
                spin_lock_irqsave(&priv->lock, flags);

diff --git a/drivers/infiniband/ulp/xsigo/xve/xve_ib.c b/drivers/infiniband/ulp/xsigo/xve/xve_ib.c
index 08c3850a20ff20b4b6e5f1240aada7eed912df14..09b822cc23da2d6a76cfd15f66854e37498d9be5 100644 (file)
--- a/drivers/infiniband/ulp/xsigo/xve/xve_ib.c
+++ b/drivers/infiniband/ulp/xsigo/xve/xve_ib.c
@@ -814,7 +814,7 @@ int xve_send(struct net_device *dev, struct sk_buff *skb,
 
                if (unlikely(skb->len > max_packet_len)) {
                        xve_warn(priv, "%s packet len %d",  __func__, skb->len);
-                       xve_warn(priv, "(> %d) too long to", priv->mcast_mtu);
+                       xve_warn(priv, "(> %d) too long to", max_packet_len);
                        xve_warn(priv, "send,dropping %ld packets %s\n",
                                        dev->stats.tx_dropped, dev->name);
                        INC_TX_DROP_STATS(priv, dev);

diff --git a/drivers/infiniband/ulp/xsigo/xve/xve_main.c b/drivers/infiniband/ulp/xsigo/xve/xve_main.c
index 67a96087b451403e95b29748f0b8f1c9a64e26b6..dad67fff015cbd96bf098b0a664742d268ae8bc1 100644 (file)
--- a/drivers/infiniband/ulp/xsigo/xve/xve_main.c
+++ b/drivers/infiniband/ulp/xsigo/xve/xve_main.c
@@ -341,39 +341,42 @@ inline void xve_get_path(struct xve_path *path)
        atomic_inc(&path->users);
 }
 
-inline void xve_put_path(struct xve_path *path, int do_lock)
+inline void xve_put_path(struct xve_path *path)
+{
+       atomic_dec_if_positive(&path->users);
+}
+
+inline void xve_free_path(struct xve_path *path, int do_lock)
 {
        struct xve_dev_priv *priv;
        struct net_device *netdev;
        struct sk_buff *skb;
        unsigned long flags = 0;
 
-       if (atomic_dec_and_test(&path->users)) {
-               netdev = path->dev;
-               priv = netdev_priv(netdev);
-               while ((skb = __skb_dequeue(&path->queue)))
-                       dev_kfree_skb_irq(skb);
+       netdev = path->dev;
+       priv = netdev_priv(netdev);
+       while ((skb = __skb_dequeue(&path->queue)))
+               dev_kfree_skb_irq(skb);
 
-               while ((skb = __skb_dequeue(&path->uplink_queue)))
-                       dev_kfree_skb_irq(skb);
+       while ((skb = __skb_dequeue(&path->uplink_queue)))
+               dev_kfree_skb_irq(skb);
 
-               if (do_lock)
-                       spin_lock_irqsave(&priv->lock, flags);
-               if (xve_cmtx_get(path)) {
-                       if (do_lock)
-                               spin_unlock_irqrestore(&priv->lock, flags);
-                       xve_cm_destroy_tx_deferred(xve_cmtx_get(path));
-                       if (do_lock)
-                               spin_lock_irqsave(&priv->lock, flags);
-               }
-               xve_flush_l2_entries(netdev, path);
-               if (path->ah)
-                       xve_put_ah(path->ah);
+       if (do_lock)
+               spin_lock_irqsave(&priv->lock, flags);
+       if (xve_cmtx_get(path)) {
                if (do_lock)
                        spin_unlock_irqrestore(&priv->lock, flags);
-
-               kfree(path);
+               xve_cm_destroy_tx_deferred(xve_cmtx_get(path));
+               if (do_lock)
+                       spin_lock_irqsave(&priv->lock, flags);
        }
+       xve_flush_l2_entries(netdev, path);
+       if (path->ah)
+               xve_put_ah(path->ah);
+       if (do_lock)
+               spin_unlock_irqrestore(&priv->lock, flags);
+
+       kfree(path);
 }
 
 struct xve_path *__path_find(struct net_device *netdev, void *gid)
@@ -529,7 +532,28 @@ void xve_flush_single_path_by_gid(struct net_device *dev, union ib_gid *gid)
 
        wait_for_completion(&path->done);
        list_del(&path->list);
-       xve_put_path(path, 1);
+       /* Make sure path is not in use */
+       if (atomic_dec_if_positive(&path->users) <= 0)
+               xve_free_path(path, 1);
+       else {
+               /* Wait for path->users to become zero */
+               unsigned long begin = jiffies;
+
+               while (atomic_read(&path->users)) {
+                       if (time_after(jiffies, begin + 5 * HZ)) {
+                               xve_warn(priv, "%p Waited to free path %pI6",
+                                               path, path->pathrec.dgid.raw);
+                               goto timeout;
+                       }
+                       msleep(20);
+               }
+               if (atomic_read(&path->users) == 0)
+                       xve_free_path(path, 1);
+
+       }
+timeout:
+       return;
+
 }
 
 void xve_flush_single_path(struct net_device *dev, struct xve_path *path)
@@ -763,7 +787,7 @@ xve_path_lookup(struct net_device *dev,
        spin_unlock_irqrestore(&xve_fwt->lock, flags);
        if (!path->ah) {
                if (!path->query && path_rec_start(dev, path)) {
-                       xve_put_path(path, 0);
+                       xve_free_path(path, 0);
                        return NULL;
                }
        }
@@ -821,7 +845,7 @@ int xve_gw_send(struct net_device *dev, struct sk_buff *skb)
        priv->counters[XVE_GW_MCAST_TX]++;
 
 out:
-       xve_put_path(path, 0);
+       xve_put_path(path);
        return ret;
 }
 
@@ -837,7 +861,7 @@ int xve_add_eoib_header(struct xve_dev_priv *priv, struct sk_buff *skb)
                if (!skb_new)
                        return -1;
 
-               kfree_skb(skb);
+               dev_kfree_skb_any(skb);
                skb = skb_new;
        }
        eoibp = (struct xve_eoib_hdr *) skb_push(skb, len);
@@ -854,7 +878,7 @@ static int xve_start_xmit(struct sk_buff *skb, struct net_device *dev)
        struct xve_dev_priv *priv = netdev_priv(dev);
        struct xve_fwt_entry *fwt_entry = NULL;
        struct xve_path *path = NULL;
-       unsigned long flags;
+       unsigned long flags = 0;
        int ret = NETDEV_TX_OK, len = 0;
        u8 skb_need_tofree = 0, inc_drop_cnt = 0, queued_pkt = 0;
        u16 vlan_tag = 0;
@@ -1009,7 +1033,7 @@ stats:
        INC_TX_BYTE_STATS(priv, dev, len);
 free_fwt_ctx:
        if (path)
-               xve_put_path(path, 0);
+               xve_put_path(path);
        xve_fwt_put_ctx(&priv->xve_fwt, fwt_entry);
 unlock:
        if (inc_drop_cnt)
@@ -1018,7 +1042,7 @@ unlock:
        if (!queued_pkt)
                dev->trans_start = jiffies;
        if (skb_need_tofree)
-               dev_kfree_skb(skb);
+               dev_kfree_skb_any(skb);
 
        spin_unlock_irqrestore(&priv->lock, flags);
        return ret;

diff --git a/drivers/infiniband/ulp/xsigo/xve/xve_tables.c b/drivers/infiniband/ulp/xsigo/xve/xve_tables.c
index ee0ce70678d7d08d05e7ff4270f502cefe4c82b8..bf6a1eed4f8efd1ea3848906dfebfd9e4f0f97cc 100644 (file)
--- a/drivers/infiniband/ulp/xsigo/xve/xve_tables.c
+++ b/drivers/infiniband/ulp/xsigo/xve/xve_tables.c
@@ -326,7 +326,7 @@ void xve_remove_fwt_entry(struct xve_dev_priv *priv,
                          struct xve_fwt_entry *fwt_entry)
 {
        struct xve_fwt_s *xve_fwt = &priv->xve_fwt;
-       unsigned long flags;
+       unsigned long flags = 0;
 
        spin_lock_irqsave(&xve_fwt->lock, flags);
        xve_debug(DEBUG_TABLE_INFO, priv, "%s Deleting FWT From list %p\n",
@@ -366,6 +366,7 @@ void xve_fwt_entry_destroy(struct xve_dev_priv *priv,
                           struct xve_fwt_entry *fwt_entry)
 {
        xve_remove_fwt_entry(priv, fwt_entry);
+       /* Function gets cald with Lock held always */
        xve_fwt_entry_free(priv, fwt_entry);
 }